During my lifetime I have seen many clever adaptations. To me, someone who says they don't have a place, probably doesn't want a layout anyhow! And that is the excuse they use to get out of it.
Under the bed, or suspended from the ceiling... there's room if you look! I especially like the pre-hung interior hollow core door, hung on a wall. Close the door, and "Look Ma, no layout!" No excuses model railroading!!!